Spoke nipple snapping.

How many spokes on the wheel? What is your typical cadence?

32 spokes, and I average 80-85 rpm.

Cadence is good, but the spoke count is pretty low for a guy your size. Check this out: http://sheldonbrown.com/wheelbuild.html Go down to the section titled "Spokes".

I can probably safely assume that this is the back wheel breaking? You need a stronger wheel built for back there. Talk to your LBS about finding a better stronger wheel. I think a custom built wheel is better then factory built but hash that out with your IBS. A rim designed for touring with 36 spokes would hold up better then the 32 spoke rim I think you have now. So find out from the LBS if they can built you a wheel designed for touring. If you want to save money the Mavic Open Sport 36 hole rims are usually good option because it will handle a 23mm tire whereas a lot of touring rims won't go that narrow which means they won't clear your brakes and maybe stays. Jenson USA sells those bare rims for $49 for black and 39 for silver. Or built with Shimano 105 hubs will cost around $200 depending on LBS charges.

Save your old rear rim because when the weight comes off you can use the rim again,

Just an option to think about.

Thanks Jpr and Froze. My bike is currently in the shop being worked on, but when I go to pick it up I will talk to them about getting a rear wheel with a higher spoke count.

The nipples are snapping? That seems odd, I have caused and witnessed plenty of wheel failures and have never seen a nipple break. By nipple, I assume you mean the part protruding from the rim that you can turn to apply tension to the spoke.

Typically the spokes themselves will break, either near the nipple or the spoke head by the hub.

Breaking nipples is not normal even for a big guy on a 32 spoke rim - I would regard the whole wheel as suspect and ask the shop to replace the wheel. If they wont replace it, at least check the tension on the spokes. With some patience you can make factory wheels stronger by evening tension, this can be done by ear with the wheel on the bike with a spoke wrench. A lot has been written on truing here and elsewhere on the web.

Sheldons' site is a good source for information, but I think some of his opinions are a bit dated. Bicycle and materials technology has advanced a lot since the 80's. 32 spokes is not a necessarily a weak wheel for a Clyde, but the wheel does have to be built right. 32 spokes are more than adequate to deal with loads placed on the wheel, the spokes will not fail due to overload. Cyclic fatigue kills the spokes over time, simply adding more spokes will not reduce this effect greatly. The wheel has to be built to minimize flexion and stress risers. I have a 28 spoke rear wheel which I have ridden hard for 4 seasons without any issues or truing. Another wheelset i use has 20 spokes on the rear and have not had any breakage over several thousand miles, but I do carry a spare spoke just in case.

I do ride a 36 rear 32 front combination on my "beater" road bike - I still get the occasional broken spoke on the rear. One advantage a 36 spoke wheel has is that the wheel is still pretty rideable if a spoke breaks.

My recommendation is to replace the wheel. If you get a factory wheel be sure to check the spoke tension. If you can upgrade for a handbuilt, go for it. Don't be surprised if the wheelbuilder recommends a 32 spoke over a 36 spoke wheel - it will still be stronger than what you have, and they will guarantee it.

I know a guy who tours at 220 pounds of his personal weight not including 60 to 70 pounds of gear. He rides on 48 spoke wheel on the back an 40 spoke wheel on the front both were built by Peter White and never had a spoke break in 9 years of touring on those wheels, and he goes at least once a year for 4 to 5 months at a time since then. Problem is most LBS's are not proficient at building wheels anymore due to the onslaught of factory built wheels, so to find a confident builder may be a challenge, you may want to ask around. Peter White is still in business, he may charge a bit more then your LBS but they will hold up if want that level of assurance. I have a set of touring wheels built by Peter White and their fantastic. But I think if you look into the Mavic Open Sport 36 hole rim, use DT Competition dble butted spokes and brass nips your problems should be solved. I recommended the Open Sport because that's the rims that Peter White uses when someone wants a narrower rim to carry a lot of weight.

I agree with Froze.

I'm 6'4" and 295. When I was riding a few years ago, I kept having problem with broken spokes. I had a new wheel build with Mavic Open Pro and Dura Ace hubs (36 spoke). After a few more spoke issues, I had one of the gentleman at the bike shop ask me if he could keep my wheel a few day so he could re-build it. After that, I haven't broken another spoke on those wheels!

Burl

As the alloy nipples self destruct, replace them with brass ones... Or see if the LBS will rebuild with brass. The spokes will likely be fine and shouldn't need to be replaced. It's not a difficult job - change one nipple at a time and true the wheel back up before doing the next. The spokes will already be seated. Add a drop of loctite 222 (not to aid with wheel reliability but to keep the crud out the spoke threads and to prevent nipple seizing) to complete a job well done. Alloy nipples have their place but that place isn't in a 28 spoke wheel with a 290lb guy on top.

Quoted post said:

Originally Posted by swampy1970 [IMG]/img/forum/go_quote.gif[/IMG]

Alloy nipples have their place but that place isn't in a 28 spoke wheel with a 290lb guy on top.

This is very true. All the wheels I've ever owned have all used brass and I'm not a heavy weight. I used brass for strength and reliability, TI nips are even better, but I've never had a problem with brass and can't see why one would need TI nips unless your wanting a lighter wheel by about 20 grams. But to use alloy nips on a bike that isn't going to see a day of racing is just plain crazy.